Abstract: A mechanism for conversion between rotary and linear motion includes a rotatable roller carriage having a channel through which a shaft is passed axially. Shaft engaging drive rollers that are orbitally movable about the channel with the rotation of the roller carriage are positioned along the channel forming an acute angle therewith. Retaining rollers are held by the roller carriage parallel to the drive rollers to retain the drive rollers in a shaft engaging position. The drive rollers are driven by the retaining rollers in a rotary fashion to linearly advance the shaft.

Abstract: A pair of wire positioning guides having spaced-apart parallel edges define a channel within which a wire is confined. A pair of wire engaging rollers are rotatably disposed along the channel on opposite sides of the guides. The rotational axes of the rollers define an acute angle with respect to the channel. Rotational movement of the rollers is thus interlocked with linear movement of the wire.